Reverse jaw expansion chuck



W. H. PECK.

REVERSE JAW EXPANSION CHUCK.

APPLICATION FILED MAR. 5, 1919.

Patented July 29, 1919.

2 SHEETS-SHEET 1.

W. H. PECK.

' REVERSE JAW EXPANSION CHUCK.

APPLICATION FILED MAR. 5,1919.

ai K mm UM of Illinois,

WILLIAM H. PECK, OF CICEKQ ILLJLNOISJ REVERSE-J AW EXPANSION-CHUCK.

Specification of Letters Patent;

Patented July 29 1919.

Application filed March 5, 1919. Serial No. 280,837.

To all whom it may concern: I

Be it known that 1, WILLIAM H. PEoK, a citizen of the United States,residing at Cicero, in the county of Cook and State have inventedcertain new and useful Improvements in Reverse-J aw Expansion-Chucks, ofwhich the following is a specification.

This invention relates to certain new-and useful improvements in chucksof a type to be used mainly on lathes, wherein a plurality of aws aremounted for radial movement and pneumatically operated in such a manneras to expand them so as to internally engage hollow work or articlessuch as pipes and the like, to be held thereby, or if desired, so thatsaid jaws may be contracted or approximated to externally grip the workor articlesand thereby firmly hold the same, and it consists in certainpeculiarities of the construction, novel arrangement and operation ofthe various parts thereof as will be hereinafter more fully set forthand specifically claimed.

The principal object of the invention is to provide a pneumaticallyoperated chuck of the above mentioned general character, which shall besimple and inexpensive n construction, strong, durable and efiicient inoperation, with its parts so made, arranged and cooperating one withanother that the, jaws thereof can be caused to grip the work eitherfrom within or from without.

Another object is to provide a chuck, which, while it is moreparticularly, intended for use in connection with lathes for holding anobject so that it can be-rotated thereby, yet is applicable for use ondrill-presses, planer-s and the like.

Other objects and advantages of the invention will be disclosed in thesubjoined description and explanation.

In. the accompanying drawings, which serve to illustrate an embodimentof the invention- Figure 1 is a central vertical sectional view of thechuck and the controlling valve thereof, showing the tubular shaft onwhich they are mounted shortened for the convenience of illustration,and exhibiting the gripping jaws, by continuous lines, in position forengagement with the work w thin the same and by dotted lines in posit onfor externally gripping the work.

Fig. 2 is a fragmental sectional vlew taken on line 2, 2 of Fig. 1,looking in the direction indicated by the arrows, showing of in positionfor expansion or for internally gripping the work. 1

Fig. 4 is an enlarged sectional View taken on line 4, 4 of Fig. 3,looking in the direction of the arrows;

Fig. 5 is a similar'view taken on line 5, 5

of Fig. 2 looking in the direction of the arrows, showing the manner ofmounting the shafts in the cylinder and its piston, for operating thejaws, and' Fig. 6 is a plan sectional view takeneon line 6, 6 of Fig. 1,showing the construction of the controlling valve and the upper portionof its casing.

Like numerals of reference refer to corresponding parts throughout thedifl'erent views of the drawings:

The reference numeral 10 designates the main or supporting shaft of thechuck, which shaft is by preference tubular in form and made of twopiecessemi-circular in cross section, which pieces are brazedorotherwise joined together at their edgesfas is clearly shown in Fig. 2of the drawings, in which view it will be noted that each of the pieces.comprising the shaft 10 is provided with a conduit which extends fromnear one end of the shaft to near the other end thereof. Each of theseconduits has its ends closed and by preference are substantiallysemi-circular in cross section, but are divided from one another bymeans of the meeting edges 11 of the pieces of the shaft. Thus. it willbe understood that the. shaft 10 is provided with a pair of conduits 12and 13 which are independent of each other. Mounted on the shaft 10 is acylinder 14 which has a centrally disposed hub 15, in which the shaft islocated and to which it may he keyed or fixed in any suitable way. Thefront end of the cylinder 14: has mounted thereon and secured to itsperiphery by means of screw bolts 16 a header end piece 17, which isprovided on its outer surface with a plurality of radial guideways 18for the reception and operation of rack bars 19, one of which is locatedin each of-said guideways for slidable movement therein. Each of thebars 19 is provided on one of its sides with a rack 20 which are for thepurpose of meshing with pinions 21, one-of which is mounted on each ofthe shafts 22 which are transversely'journaled in the rear end piece orhead 23 of the cylinder 14, and'in the front end piece or head 17thereof, and

other end; thereof, as ,is clearly shown in Figs. 1 and 5 of thedrawings. The rear end of each shaft 22 has its rear bearing 25 in therear end or head 23 of the cylinder, and each of said shafts issurrounded near its rear end by a pair of spaced-apart metallic rings26, between which. are located-a series of anti-friction balls 27. Theouter end of each of the shafts 22 is reduced outwardly from the pinion21 on'saidshaft and has mounted thereon a bearing collar 28 which isscrewed into asuitable opening-27 in the head 17, which opening is ofsuflicient size to permit of the insertion of the pinion on' the shaft,which pinion, as before stated, meshes withthe rack 20 on the rack bar19 adjacent thereto. Surrounding each of the shafts 22 is a collar oracking ri 29 of leather or other suita 'le materia which ring or collaris partly located in the opening 30 in the head 17 for the shaft 22, andpartly in the inner end of the. enlarged openlng 27 and is held inposition by means of a ring 31 surrounding the shaft and screws 32 whichengagethe head 17 of the c linder. Located between the .collar and t eface of the gear 21 adjacent thereto are anti-friction balls 33, whichare heldin place by means of grooved rings 34 on the inner end of thecollar 28, which collar can be suitably adjusted by means of a spannerwrench or other instrument inserted in openings 35 in said collar.

Slidably mounted on the hub 15 of the cylinder is a piston or plunger36, which has transverse openings therein at suitable points to receivethe shafts 22, upon which said piston is also slidably mounted. At itsouter periphery the plston 36 is provided on each of its sides with anannular recess 37 in which are located packing rings 38 of leather orother suitable material, which rings are held in position by means ofmetal rings 39 located on the sides of the piston and by means of screwbolts 40 extended through said rings and the piston. The inner peripheryof the piston 36 is similarly formed and equipped with packing rings ofthe same construction as above mentioned for the outer periphery of thepiston. Located in each of the grooves 24 of each of the shafts 22 is aball 41, which are inserted through suitable screw threaded openings 42radially located in the piston'36 near the rear end of each of theopenings therein for the shafts 22, and said balls are retained inposition by means of a grooved member 43, each of which is held in placeby a screw 44 engaging the openings 42. The front portion of the piston36 is provided around each of the shafts 22 with a screw threadedopening 45. for the rece tion of suitable packing 46 and a gland 4for'holding the same in position. I

Mounted on the outer surface of each of the rack bars 19 is a grippingjaw 48, each of which is by preference formed with steps 49 on its outersurface to engage the work or article to be held by the clutch. Each ofthese gripping jaws is detachably secured to its respective rack bar bymeans of screw bolts 50 extended through said jaws and engaging saidbars. By this arrangement it will be understood that by removing thescrew bolts 50 from the bars 19 the positions of the jaws 48 may bereversed, when they can again be secured to the rack bars by means ofthe screw bolts. It will be understood that when the jaws are in thepositions shown by continuous lines in Fig. 1 of the drawings, they willbe ready for engagement with the work or article to be held from within,and that by reversing the position of the jaws to that shown by dottedlines in said figure, the said jaws will be in osition to engage or gripthe work externa 1y. Y

The cylinder may be fixed to the head plate or "suitable part 51 (seedotted lines in Fig. l of the drawing) of the lathe or other machine inconnection with which' the chuck is used by -means of screw bolts 52engaging suitable openings in the rear end of the cylinder.

As shown in Fig. 1, the rear end head 23 of the cylinder is providedwith a port 53 which communicates with the conduit 13 of themain shaft10 and leads into the cavity of the cylinder at the rear of the piston36 therein. The inner surface of the front head. or end piece 17 of thecylinder is provided with a port 54 which communicates with the conduit12 of the main shaft, and leads into the cavity of the cylinder in frontof the piston therein.

In order to limit the strokes of the piston the front head 17 'of thecylinder and the rear head 23 thereof maybe provided with a plurality ofopenings 71 for the reception "of screws 2, which are countersunk attheir outer ends in the outer surfaces of said heads or cylinder ends,and each set of said screws may extend a suitable distance from theinner surfaces of the heads on each side of the piston so as to stop itsmovement in either direction. By this arrangement, it is inner surfacesof the ends thereof. It is also manifest that if it is desired to omitthe screws. 72 so as to permit the piston to have movement equal to thelength of the cylinder, said screws can be removed and their openings 71closed by means of short screws or screw plugs 7 3, as is shown in therear head in Fig. 1 of the drawings. While I prefer to employ thesescrews for limiting the movement of the piston in either direction, yetit is obvious that they may be omitted from one of the heads and used inthe other head only.

Surrounding the shaft 10, but soas to permit the sameto rotate thereinare a air of casings, each of which is composed 0 an annular orring-like member 55, having on each of its sides an externally screwthreaded flange 56 with each of which an annular collar or cap 57engages. Each of the members 55 has on its inner surface acircumferential groove 58, one of which grooves has communicationthrough a ort 59 inthe shaft 10 leading to the condult 12 thereof,

and the other of said grooves has communication through a port 60 withthe conduit 13 of said shaft. Located between each of having a pa1r oflongitudinal conduits the caps or rings 57 and each of the flanges 56 isa packing ring 61 of any suitable material, which will prevent leakageof the compressed air or fluid {undier pressure, which passes throughthe members 55 and the conduits of the main shaft. Each of the memhers55 has a hollow stem 62 extended ther'efrom which are connected by meansof suitable pipes 63to a valve casing 64, which has connected thereto aninlet pipe 65 leading from a supply of fluid under pressure (not shown;see Fig. 6). This casing also has an outlet or exhaust port 66, and isprovided with channels or ports 67 and 68 which communicate through thepipes 63 with the grooves 58 of the members 55 surrounding the mainshaft. Located in the casing 64 is a valve 69 which may have a handle 0for turning the same so as to open and close the channels 67 and 68alternately.

From the foregoing and by reference to the drawings, it will be readilyunderstood and clearly seen that, assuming that the parts are in thepositions shown in Fig. 1 of the drawings, and it is desired to causethe gripping jaws a8 to engage the work to be held internally, whichwork it will be assumed is in position around one of the steps $9 ofeach of said jaws, it is only necessary to turn the valve 69 to theposition shown in Figs. 1 and 6 of the drawings, when it is obvious thatthe compressed air or fluid under pressure supplied through the pipe 65,channel 68-of the valve casing 61, andthrough the groove of the member58, adjacent to the cylinder, will enter the conduit 13 of the mainshaft and pass therefrom through the port 53 of the cylinder, thusforcing the piston 36 forwardly, in which operation the balls 41 carriedby the piston and operating in the grooves 24 of the shafts 22, willcause said shafts to rotate and through the engagement of the pinions 21on said shafts with the racks 20 of rack bars, will cause said bars tobe moved outwardly, thus expanding the gripping jaws 48 against theinner surface of the work. \Vhen it is desired to release the grippingjaws, the valve ,69 should be turned to open the channel67 to the inletpipe 65, which operation will permit the fluid under pressure to passthrough the conduit 12 into the front portion of the cylinder and forcethe piston 36 thereof rearwardliy, in which- -operat1on it will beunderstood that the air or fluid located between the rear surface of thepiston and the rear head or end thereof will be exhausted'through theport 53, the conduit 13,- the port 60, channel 58, and from thencethrough the exhaust port 66 of the valve casing,

Having thus fully described my invention what 1 claim as new and desireto secure by Letters Patent is 1. The combination with a main shaftadapted for communication with a supply of fluidunder pressure, of acylinder mounted on said shaft and having ports communicating withsaid-conduits and provided at one of its. endswith a, plurality ofradial guideways,-a plurality of shafts journaled in the ends of the clinder on correspondng sides of said guldeways and each having a pair ofoppose'dand spirally extended grooves, a pinion on each of said shafts,a rack bar slidably mounted in each guideway in mesh with said pinions,a jaw mounted on each of said rack bars,a piston mounted in the cylinderbetween the ports thereof and having openings for said shafts, a balllocated in each of the grooves of each of the pinion carrying shafts,means communicatively connecting the said conduits with a supply offluid under pressure, and a controlling valve located in said means.

2. The combination with a main shaft having I a pair of longitudinalconduits adapted for communication with a supply of fluid underpressure. of a cylinder mount ed on said shaft and having portscommunieating with said conduits and provided at one of its ends with aplurality of radial guidcways, a plurality of shafts journaled in theends of the cylinder on corresponding the j Y I 1,311,665

sides of said guideways and each having a pair of opposed and spirallyextended grooves, a pinion on each of said shafts,

a rack bar slidably mounted in each-guideway in mesh with said pinions,a stepped jaw mounted on each of said rack bars, a piston mounted in thecylinder between the ports thereof and having openings for sald shafts,a ball located in each of the grooves vided at one of its ends with aplurality ofguideways, shafts journaled in the ends of the cylinder oncorresponding sides of said guideways and each having a pair of opposedand spirally extended grooves, a pmion on each of said shafts, a rackbar slidably mounted in each guideway in mesh with said pinions, a jawmounted on each of said rack bars, a piston mounted in the cylinderbetween the ports thereof and having openings for said shafts, a balllocated in each of the grooves of each of the pinion carrying shafts, avalve mechanism mounted on the main shaft and having communication withthe conduits thereof and provided with an inlet and exhaust port, and acontrolling valve mounted on said mechanism between said ports. 7

t. The combination with a main shaft having a pair of longitudinalconduits adapted for communication with a supply of fluidunder-pressure, of a cylinder mounted on said shaft and having portscommunicating with said conduits and provided at one of its ends with aplurality of radial guideways, a plurality of shafts journaled in theends of the cylinder on corresponding sides of said guideways and eachhaving a pair of opposed and spirally extended grooves, a pinion on eachof said shafts, a rack bar slidably mounted in each guideway in meshwith said pinions, a stepped jawdetachably mounted on each of said rackbars, a piston mounted in the cylinder between the ports thereof andhaving openings for said shafts, aball located in each of the grooves ofeach of the pinion carrying shafts, a valve mechanism mounted on themain shaft and having communication with the conduits thereof andprovided with an inlet and exhaust port, and a controlling valve mountedon said mechanism between said ports. 7 i

5. The combination with a supporting shaft having a pair of longitudinalconduits, of a cylinder axially mounted thereon and having portscommunicating with said conduits and provlded at one of its ends with aplurality of radlal guideways, a-

plurality of shafts journaled in the ends of the cylinder between saidguideways and each having a pair of opposed grooves spirally extendedthereon in opposite directions, a pinion on each of said shafts, a rackbar slidably mounted in each guideway and in mesh with said pinions, agripping jaw detachably mounted on each rack bar, a

piston mounted in the cylinder between the ports thereof and havingopenings for said shafts, a ball located in each of the grooves of eachof the pinion carrying shafts and carried by the piston, a pair ofcasings surrounding the supporting shaft and each having a passagewayindependently communicating with the conduits of said shaft, aconnection uniting said passageways and having an inlet portcommunicating with a supply of fluid under pressure and an ex- 'haustport, and a controlling valve located in said connection between thepassageways of the casings and between said inlet and exhaust ports.

6. The'combination with a main shaft having a pair of longitudinalconduits, of a cylinder mounted on said shaft and having portscommunicating with said conduits and transversely extended screwthreaded openings .in at least one of its heads and provided at one ofits ends with a plurality of radial guideways, screws located in saidopenings, a plurality of shafts journaled in the ends of the cylinder oncorresponding sides of said guideways and each having a pair of opposedgrooves spirally extended thereon in opposite directions, a pinion oneach of said shafts, a rack bar slidably mounted in each guideway inmesh with said pinions, a jaw mounted on each of said rack bars, apiston mounted in the cylinder between the ports thereof and havingopenings for said shafts, a ball located in each of the grooves of eachof the pinion carrying shafts and carried by the piston, meanscommunicatively connecting the said conduits with a supply of fluidunder pressure, and a controlling valve located in said means.

't'. The combination with a main shaft having a pair of longitudinalconduits, of

a cylinder mounted on said shaft and hav-' ing ports communicating withsaid conduits and transversely extended screw threaded a plurality ofshafts journaled in the ends of the cylinder on correspondingsides ofsaid guideways and each having a pair of opposed grooves spirallyextended thereon in opposite directions, a pinion on each of shafts andcarried by the said shafts, a rack bar slidably mounted in each guideway1n mesh Wlth said pinlons, a aw mounted on each of said rack bars,

a piston mounted in the cylinder betweenv the ports thereof and havingopenings for said shafts, a ball located in each of the grooves of eachof the pinion carrying piston, a valve mechanism mounted on the mainshaft and having communication with the conduits 10 thereof and providedwith an inlet from a supply of fluid under pressure and an eX- hanstp0rt,- and a controlling valve mounted on said mechanism between saidinlet and exhaust port.,

, WILLIAM H. PECK.

